Addressing new research issues in studies of community-based drug abuse treatment requires very sophisticated theory and concepts, research designs, measurement, and analysis strategies. Few individual grant or contract studies have had or will have sufficient resources to systematically and comprehensively consider the complex methodological issues that often threaten the integrity of research results in community-based treatment research. This research is necessarily conducted outside clinical research centers and addresses basic applied issues rather than the generation of new therapeutic approaches. The primary goal of the Center for the Advancement of Treatment Evaluation Methods will be to identify, develop, assemble, apply, and disseminate knowledge about state-of-the-art methods for research on drug abuse treatment in typical community-based programs. The secondary goal of this Center will be to understand the nature and extent of bias and error resulting from the use of a specific methodology and the integrity of its application in community-based treatment research. To accomplish these goals, the Center will coordinate and integrate four projects: To examine the nature and extent of bias and error due to recall and denial in self-reports of client behavior before, during, and after treatment; To determine the sensitivity of estimates of treatment effects by assessing the impacts of various treats to the integrity (such as attrition, compliance, self-selection) of randomized field trials, quasi-experimental, and clinical epidemiological evaluation designs; To consider the sensitivity of common multivariate analytic strategies to alternative models specification, data correction procedures, and the use of different statistical techniques; and To expand the refine benefit-cost and cost-effectiveness frameworks by incorporating additional outcomes (such as health and employment) and more detailed cost estimates for programs, service components, and clients. Initially the Center will focus the methodological work on two key research issues: How do client impairments affect treatment process and outcome? How does the treatment structure and process affect outcomes? Two other projects, included in the original Center application of March, 1991 were resubmitted as independent grant applications and, if funded, will become components of the Center. To assess the reliability and validity of self-report measures of psychiatric, vocational, medical and other impairments for research, clinical and program management uses; To identify the most appropriate ways to measure the nature of treatment structure and process across multisite samples of programs providing the major types of treatment.